I agree with Malcore, recognition for sponsors is probably not a good idea. Those who do pay will know that they have done their bit, and those who don't will not be able to use the "well, you pay so you get ******* , and it isn't fair!" argument. Look at the thread about avatars!
And, again, it could lead to newcomers thinking that they had to pay to use the site. I know that is NOT the intention, but based on some bad experiences elsewhere, I think it could happen.
be wary of strong drink - it may make you shoot at tax collectors, and miss!